[vsnet-grb-info 2061] GRB 050827: Optical Limit

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3900
SUBJECT: GRB 050827: Optical Limit
DATE:    05/08/28 20:04:21 GMT
FROM:    Jules Halpern at Columbia U.  <jules at astro.columbia.edu>

J. P. Halpern (Columbia U.) reports on behalf of the MDM Observatory
GRB follow-up team:

"I observed the error box of GRB 050827 (Swift trigger #152325, GCN #3893)
in the R band with the MDM 1.3m telescope for 50 minutes starting on
Aug. 28 09:32 UT, or 14.6 hours after the burst.  There is no optical
object to a limiting magnitude R=23.5 within 16", or twice the error circle 
radius, of the XRT candidate afterglow reported by Capalbi et al. (GCN #3899).  
Even after correcting this limit for Galactic absorption A(R)=1.47 mag at its
location (Schlegel et al. 1988), it would be unusual for a persistent X-ray 
source of flux 1.0E-12 erg cm^-2 s^-1 to have no optical counterpart.  So
this supports the identification of the X-ray source as the GRB afterglow."